TWO GERMAOXETANES FROM A GERMENE : FORMATION AND STRUCTURE

Dimesitylfluorenylidenegermane (1) reacts very readily with aldehydes and ketones, according to a [2+2] cycloaddition, leading to the corresponding germaoxetanes. These four-membered-ring heterocycles are quite stable, mainly due to the large steric hindrance of the substituents. In the case of acetone, reaction with the enolic form has been observed, followed by a germanotropic rearrangement